Use “id.” for the book cited above

Style note²Federal courts, Illinois courts21st and 22nd editions

A book that is the sole authority in the citation immediately before it is cited again as “id.” with just the pincite changed, not as “supra,” which is for a full citation standing further back.¹

1. 1B15.2 Short Form Citation. Tables: R. 4.1 “Id.”; R. 4.2(a) “Supra.”; R. 15.10 Short Citation Forms.
2. 2A style note: the rule in note 1 allows both forms and prefers one.